Process op purifying nitrogen



NATHANIEL T. BASON, OF

PBOCES$ COMPANY, OF

rnoonss or PEACE DALE, RHODE ISLAND, ASSIGNOR TO 'SOLVAY SOLVAY, NEW YORK, A

CORPORATION OF NEW YORK.

PURIFYING NITROGEN.

No Drawing.

To all to [1.0% it may concern Be it known that I, NATHANIEL T. Bacon,

a citizen of the United States, residing at Peace Dale, in the county of Washington and State of Rhode Island, have invented a new and Improved Process of Purifying Nitrogen, of which the following is a specification.

My invention relates to the recovery of nitrogen of such purity as to be suitable for use in the Well known fixation processes and the object of my improvement specifically is to eliminate free oxygen and oxygen compounds which are particularly detrimental to the carrying out of such processes. in carrying my invention into effect I employ as the source of nitrogen the ordinary lime kiln operation in the gaseous product of which nitrogen is the principal constituent. in the burning of the limestone I use an. excess of coke above that required to effect the reaction which may go as high as 20 per cent, so as to reduce to a trace the free oxygen present. This Will result in the formation of a small quantity of CO gas but as this is unaltered in the processes for which the nitrogen is to be employed it may be looked upon simply as a diluent, as may also the small quantities of the inert gases, argon, helium. etc., and may be disregarded, .eaving CU, as the only considerable impurity present with the nitrogen. l then remove the G0,, which in the fixation Process would give up oxygen and thusjnterfore with the result, by \vashiiig the gas in a strong solution of :m'nnonium hydrate, as by causing it to bubble up through the solu tion in an ordinary Wash tower.

Such excess of the sohition should be employed-that after washing the gas it shall carry at least 20 per cent. of the ammonia present ammo nun hydrate. Under these conditions practically all of the CO will be absorbed in the liquor with formation of ammonium monocarbonate.

Th nitrogen should then be washed with waterin a separate washer to remove traces of ammonia and after settling out the Water in suspension, with precautions to prevent other gases from becoming mixed with it, is ready to go into consumption.

in order to obtain the best results the wash liquor should be kept at a relatively Specification of Letters Eatent.

Patented Illay 27, 1919.

Application filed November 27, 1917. Serial No. 204,142.

say 2.5 (1., as by means of cooling coils and the absorption otthe 00 will also be made more complete by effecting it unt er pressure. At the temperature given above a pressure of not much more than one atmosphere suliicient, but at higher temperatures anincrcase oi? pressure is desirable. The carbonated liquor can be used for the formation of ammonium nitrate with the calcium nitrate from the recovery 0. nitric acid fumes, or in any other manner.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The process of obtaining purified nitrogen which consists in separating nitrogen. of the atmosphere from free oxygen by burning limestone with an excess of coke and absorbing the CO content of the gaseous product in a solution of ammonium hydrate.

2. lhe process oi obtaining purified nitrogen which consists in separating nitrogen of the atmosphere from tree oxygen by burning limeston with an excess of colic andabsorbing the ()0 content of the gaseous product in a solution of ammonium hydrate in excess.

3. The process of obtaining purified nitrogen which consists in separating nitrogen of the atmosphere from free oxygen by burning limestone with an excess of coke and absorbing the CO, content of the gaseous product in a cooled solution of ammonium hydrate in excess.

4. lhe process of obtaining purified nitro gen which consists in separating nitrogen o the atmesphere from free oxygen by burning limestone with an excess of cokeand absorbing the CO content of the gaseous product under pressure ina solution of ammonium hydrate in excess.

T he process of obtaining purified nitro gen which consists in separating nitrogen o the atmosphere from free oxygen by burning limestone with an excess of coke and causing the absorption of the CO. content of the gaseous product in a cooled solution of ammonium hydrate in excess and under pressure.

in testimony whereof I have aiiixed my signature. this 19th day of November 1917.

NATHANIEL 'r. BACON.

low temperature, 

